Reverse Geocode Online

This sample demonstrates reverse-geocoding points using a LocatorTask. To use the sample, simply click on or near a street in the map. When a result is found, it will be drawn on the map with the returned address in the graphic's MapTip.

In the code-behind, a LocatorTask is used to perform an address lookup operation for the clicked point. When a result is returned, a graphic is added to the map, and the address is added to the graphic's attributes such that it shows up in the graphic's MapTip.

XAML

<UserControl x:Class="ArcGISWPFSDK.LocationToAddress"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
   xmlns:esri="http://schemas.esri.com/arcgis/client/2009">
    <Grid x:Name="LayoutRoot" Background="White" >

        <Grid.Resources>
            <esri:PictureMarkerSymbol x:Key="DefaultMarkerSymbol" OffsetX="12" OffsetY="12" Source="/Assets/Images/x-24x24.png" />
            <LinearGradientBrush x:Key="PanelGradient" EndPoint="0.5,1" StartPoint="0.5,0">
                <LinearGradientBrush.RelativeTransform>
                    <TransformGroup>
                        <ScaleTransform CenterY="0.5" CenterX="0.5"/>
                        <SkewTransform CenterY="0.5" CenterX="0.5"/>
                        <RotateTransform Angle="176" CenterY="0.5" CenterX="0.5"/>
                        <TranslateTransform/>
                    </TransformGroup>
                </LinearGradientBrush.RelativeTransform>
                <GradientStop Color="#FF145787" Offset="0.16"/>
                <GradientStop Color="#FF3D7FAC" Offset="0.502"/>
                <GradientStop Color="#FF88C5EF" Offset="0.984"/>
            </LinearGradientBrush>
        </Grid.Resources>

        <esri:Map x:Name="MyMap" Background="#FFE3E3E3" MouseClick="MyMap_MouseClick" WrapAround="True">
            <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" 
                    Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer" />
            <esri:GraphicsLayer ID="LocationGraphicsLayer">
                <esri:GraphicsLayer.MapTip>
                    <Grid Background="LightYellow">
                        <StackPanel Orientation="Vertical" Margin="5" >
                            <TextBlock Text="{Binding [Address1]}" HorizontalAlignment="Left" Foreground="Black" />
                            <TextBlock Text="{Binding [Address2]}" HorizontalAlignment="Left" Foreground="Black" />
                            <TextBlock Text="{Binding [LatLon]}" HorizontalAlignment="Left" Foreground="Black" />
                        </StackPanel>
                        <Border BorderBrush="Black" BorderThickness="1" />
                    </Grid>
                </esri:GraphicsLayer.MapTip>
            </esri:GraphicsLayer>
        </esri:Map>

        <Grid HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,15,15,0" Width="350" >
            <Rectangle Fill="{StaticResource PanelGradient}" Stroke="Gray"  RadiusX="10" RadiusY="10" Margin="0,0,0,5">
                <Rectangle.Effect>
                    <DropShadowEffect/>
                </Rectangle.Effect>
            </Rectangle>
            <Rectangle Fill="#FFFFFFFF" Stroke="DarkGray" RadiusX="5" RadiusY="5" Margin="10,10,10,15" />
            <TextBlock x:Name="InformationText" Text="Click on or near a street in the map to define a location. The address of the location will be displayed in a MapTip when the cursor hovers over the marker." 
                HorizontalAlignment="Center" VerticalAlignment="Top" TextAlignment="Left" Margin="30,20,20,30" TextWrapping="Wrap" Foreground="Black"/>
        </Grid>

    </Grid>
</UserControl>

C#

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Geometry;
using ESRI.ArcGIS.Client.Tasks;

namespace ArcGISWPFSDK
{
    public partial class LocationToAddress : UserControl
    {
        private static ESRI.ArcGIS.Client.Projection.WebMercator _mercator =
                                new ESRI.ArcGIS.Client.Projection.WebMercator();
        GraphicsLayer _locationGraphicsLayer;

        public LocationToAddress()
        {
            InitializeComponent();

            ESRI.ArcGIS.Client.Geometry.Envelope initialExtent =
                    new ESRI.ArcGIS.Client.Geometry.Envelope(
            _mercator.FromGeographic(
                    new ESRI.ArcGIS.Client.Geometry.MapPoint(-117.387, 33.97)) as MapPoint,
            _mercator.FromGeographic(
                    new ESRI.ArcGIS.Client.Geometry.MapPoint(-117.355, 33.988)) as MapPoint);

            initialExtent.SpatialReference = new SpatialReference(102100);

            MyMap.Extent = initialExtent;

            _locationGraphicsLayer = MyMap.Layers["LocationGraphicsLayer"] as GraphicsLayer;
        }

        private void MyMap_MouseClick(object sender, ESRI.ArcGIS.Client.Map.MouseEventArgs e)
        {
            Locator locatorTask = new Locator("http://tasks.arcgisonline.com/ArcGIS/rest/services/Locators/TA_Streets_US/GeocodeServer");
            locatorTask.LocationToAddressCompleted += LocatorTask_LocationToAddressCompleted;
            locatorTask.Failed += LocatorTask_Failed;

            // Tolerance (distance) specified in meters
            double tolerance = 30;
            locatorTask.LocationToAddressAsync(e.MapPoint, tolerance, e.MapPoint);
        }

        private void LocatorTask_LocationToAddressCompleted(object sender, AddressEventArgs args)
        {
            Address address = args.Address;
            Dictionary<string, object> attributes = address.Attributes;

            Graphic graphic = new Graphic()
            {
                Symbol = LayoutRoot.Resources["DefaultMarkerSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol,
                Geometry = args.UserState as MapPoint
            };

            string latlon = String.Format("{0}, {1}", address.Location.X, address.Location.Y);
            string address1 = attributes["Street"].ToString();
            string address2 = String.Format("{0}, {1} {2}", attributes["City"], attributes["State"], attributes["ZIP"]);

            graphic.Attributes.Add("LatLon", latlon);
            graphic.Attributes.Add("Address1", address1);
            graphic.Attributes.Add("Address2", address2);

            _locationGraphicsLayer.Graphics.Add(graphic);
        }

        private void LocatorTask_Failed(object sender, TaskFailedEventArgs e)
        {
            MessageBox.Show("Unable to determine an address. Try selecting a location closer to a street.");
        }
    }
}

VB.NET

Imports System.Collections.Generic
Imports System.Windows
Imports System.Windows.Controls
Imports ESRI.ArcGIS.Client
Imports ESRI.ArcGIS.Client.Geometry
Imports ESRI.ArcGIS.Client.Tasks
Namespace ArcGISWPFSDK
    Partial Public Class LocationToAddress
        Inherits UserControl
        Private Shared _mercator As New ESRI.ArcGIS.Client.Projection.WebMercator()
        Private _locationGraphicsLayer As GraphicsLayer

        Public Sub New()
            InitializeComponent()

            Dim initialExtent As New ESRI.ArcGIS.Client.Geometry.Envelope(TryCast(_mercator.FromGeographic(New ESRI.ArcGIS.Client.Geometry.MapPoint(-117.387, 33.97)), MapPoint), TryCast(_mercator.FromGeographic(New ESRI.ArcGIS.Client.Geometry.MapPoint(-117.355, 33.988)), MapPoint))

            initialExtent.SpatialReference = New SpatialReference(102100)

            MyMap.Extent = initialExtent

            _locationGraphicsLayer = TryCast(MyMap.Layers("LocationGraphicsLayer"), GraphicsLayer)
        End Sub

        Private Sub MyMap_MouseClick(sender As Object, e As ESRI.ArcGIS.Client.Map.MouseEventArgs)
            Dim locatorTask As New Locator("http://tasks.arcgisonline.com/ArcGIS/rest/services/Locators/TA_Streets_US/GeocodeServer")
            AddHandler locatorTask.LocationToAddressCompleted, AddressOf LocatorTask_LocationToAddressCompleted
            AddHandler locatorTask.Failed, AddressOf LocatorTask_Failed

            ' Tolerance (distance) specified in meters
            Dim tolerance As Double = 30
            locatorTask.LocationToAddressAsync(e.MapPoint, tolerance, e.MapPoint)
        End Sub

        Private Sub LocatorTask_LocationToAddressCompleted(sender As Object, args As AddressEventArgs)
            Dim address As Address = args.Address
            Dim attributes As Dictionary(Of String, Object) = address.Attributes

            Dim graphic As New Graphic() With { _
             .Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol), _
             .Geometry = TryCast(args.UserState, MapPoint) _
            }

            Dim latlon As String = [String].Format("{0}, {1}", address.Location.X, address.Location.Y)
            Dim address1 As String = attributes("Street").ToString()
            Dim address2 As String = [String].Format("{0}, {1} {2}", attributes("City"), attributes("State"), attributes("ZIP"))

            graphic.Attributes.Add("LatLon", latlon)
            graphic.Attributes.Add("Address1", address1)
            graphic.Attributes.Add("Address2", address2)

            _locationGraphicsLayer.Graphics.Add(graphic)
        End Sub

        Private Sub LocatorTask_Failed(sender As Object, e As TaskFailedEventArgs)
            MessageBox.Show("Unable to determine an address. Try selecting a location closer to a street.")
        End Sub
    End Class
End Namespace